856566165 has 64 divisors (see below), whose sum is σ = 1786046976. Its totient is φ = 340180992.

The previous prime is 856566157. The next prime is 856566167. The reversal of 856566165 is 561665658.

It is not a de Polignac number, because 856566165 - 2³ = 856566157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856566167) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4749 + ... + 41661.

It is an arithmetic number, because the mean of its divisors is an integer number (27906984).

Almost surely, 2^856566165 is an apocalyptic number.

856566165 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

856566165 is an abundant number, since it is smaller than the sum of its proper divisors (929480811).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856566165 is a wasteful number, since it uses less digits than its factorization.

856566165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36958.

The product of its digits is 1296000, while the sum is 48.

The square root of 856566165 is about 29267.1516379712. The cubic root of 856566165 is about 949.7011673200.

The spelling of 856566165 in words is "eight hundred fifty-six million, five hundred sixty-six thousand, one hundred sixty-five".